book Maths Puzzle Numerical Ability

I am unclear as how to do this thanks for any help.
Graph the solution set of x < -4.

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book Other Question

The sum of two numbers is 21. When the larger number is subtracted from four times the smaller number, the difference is 4. What are the two numbers? give 2 points on the line with the givin equation, then graph the line.
y=-4x+6

i dont no how 2 do any of this